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skydived19006

Malfunctioned Drogue

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I searched around, and couldn’t find anything on this “problem.” I had an malfunctioned drogue Saturday, caused by the drogue bridle half hitching around the edge of the drogue, quite affectively turning it into a next to zero drag rag. This has happened to me twice in the last two months, zero in the preceding 2000 tandems. Once can be chalked up to freak thing, but twice in as many months virtually has to be attributed to packing. We reviewed how we prefer to pack the drogue with everyone, so hopefully we can go another 4000 tandems without seeing this again!! I’m curious how common malfunctioning drogues are, in particular caused by bridle knots. I shot a couple of pictures of the drogue once on the ground, but they’re still at the DZ in my Sony PC, so not attached.

Here’s the story:
We leave the airplane and I throw the drogue, but damn if we didn't keep accelerating! So, time to start pulling handles in order (curios if anything thinks that it would be appropriate to go directly to the reserve), I pulled the drogue release, and after a couple of seconds we were nailed by main canopy deployment. My student even lost a shoe, but they were slip on, so not tight shoes. We were something above 6,000, but I think we were down to around 9,000 by the time we exited, I figure I pulled the drogue release within 10 seconds off the airplane. So, good main! Not really, I'm looking at about 10 turns of line twists now, the bag must have been twisting around under that rag of a drogue. We start working on the line twists, which really was not going well at all. I had the student trying to help, but we'd get it going, get one turn, then stop again. Something I had read on dropzone.com reminded me that we were trying to turn against the "wind vain effect" (dropzone.com may have saved me a reserve ride!). With a canopy in full flight (Icarus 365), and especially since my student was over 200 lbs (475/485 suspended), our knees/legs were keeping us from turning out of the twists. So, by about 4,000' I asked Jorge to try to "stand up" in the harness, and I did the same, to get our legs out of the wind, and finally we got it turning out of line twists, and cleared by 3,000'. I would have liked to have chopped above 3,000, but it was apparent that we were going to clear the twists and be fine.

The first time this happened to me, the drogue was producing enough drag that I felt it stabilizing us, had hand cam, but went to my primary function and didn’t get good video of the drogue. You do see the main bag almost bump me on the back of the head as it very lazily “launches.” The second time (Saturday) I could tell there was something above us, but very little stabilizing drag. My fear is that there wouldn’t be enough drag to deploy the canopy, hopefully enough to make the three rings let go. I really don’t want to be standing up in freefall with a student, and trying to make the three rings let go by hand, possibly having the RSL deploy the reserve, with the main bag in tow still with me. Am I over analyzing this? Thoughts?

To date something like 2500 tandems (need to catch up my log book), and zero reserve rides. Two malfunctioning drogues, and a few other “glitches” but nothing I cut away from as yet.

Martin
Experience is what you get when you thought you were going to get something else.

AC DZ

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I haven't seen it.

Are you packing your tandems or is the DZ packing kid?

I wonder if he's not putting the bridle inside of the drogue in some fashion (yes there are about 1000 ways to do this and most work well). I'm also wondering if he's putting the drogue in "backward" to the bridle so that the bridle is exiting the bottom of the drogue bundle and exiting around the spandex side instead of the container side of the packed drogue?
--"When I die, may I be surrounded by scattered chrome and burning gasoline."

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We recently lost our primary packer to a real world job, so have a 3 skydivers packing. How we pack the drogue is to fold quarters into the center, then in half, S-fold the bridle on that (top fabric), then sides in thirds and roll up. Bridle comes out the bottom, and goes into the pouch.

Martin
Experience is what you get when you thought you were going to get something else.

AC DZ

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I am not sure if what system you are jumping, but we had this happen a couple of times last year. Our rigger figures that it was caused from the S folded bridal extending beyond the edges of the drogue so it can half hitch around it, by keeping the S folds in from the edges we have not had another problem. I have attached a drawing for how we fold our drugues on Sigma rigs.
Kirk
He's dead Jim

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Never had it before this year, and it's now twice this year for me. Pulled within 10 seconds, had a slow to line stretch, then normal or brisk opening.

I would NOT recommend going straight to reserve.

We've reviewed drogue packing with our packers.
----------------------------------------------
You're not as good as you think you are. Seriously.

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I am not sure if what system you are jumping, but we had this happen a couple of times last year. Our rigger figures that it was caused from the S folded bridal extending beyond the edges of the drogue so it can half hitch around it, by keeping the S folds in from the edges we have not had another problem. I have attached a drawing for how we fold our drugues on Sigma rigs.



They're Eclipse rigs which are pretty much a clone of a Vector II, and this was a Vector drogue.

Your drawing depicts how we pack drogues, with a slight difference. I'll emphasize keeping the bridle away from the edges with everyone.
Experience is what you get when you thought you were going to get something else.

AC DZ

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Never had it before this year, and it's now twice this year for me. Pulled within 10 seconds, had a slow to line stretch, then normal or brisk opening.

I would NOT recommend going straight to reserve.

We've reviewed drogue packing with our packers.



The first time I had this, the first thing to flash into my head was 'reserve!' Cooler mind prevailed thinking 'not yet, release the drogue and see what happens'

The one Saturday provided very little drag, and the time from drogue release to hard opening was a fair bit, things are moving fast so hard to say exactly how long, maybe 2 to 3 seconds, just barely enough drag to make it happen.

Martin
Experience is what you get when you thought you were going to get something else.

AC DZ

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This same thing caused the Ron Green fatality. He was the examiner with a candadate on the back. They had a knotted drouge and the reserve pilot chute tangled with it.

He had 4000 tandems and 14000 jumps.
He who hesitates shall inherit the earth.

Deadwood
Skydive New Mexico Motorcycle Club, Touring Division

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The candidate dumped the reserve into the drogue instead of releasing it. She taught my AFF ground school. First person I knew to die skydiving. Happened at my home DZ (Cedar Valley, UT). Had the drogue been released they probably would have landed the main.

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This (below quote) was sent to me in a PM. I normally would not cut/paste a PM, I'll leave it anonymous , and I don't see it as anything stated that would cause any issue.

It had not occurred to me that when base jumping, a malfunctioned pilot chute more than likely means your on your last jump.

Base and tandem drogue deployment do not totally equate in my mind. When throwing a tandem drogue, if you put it out at arms extension, and don't REALLY rush the throw, I'm thinking that the bridle will be in the air in a large "horse shoe" from the drogue up and down to the three ring/disk. I'll admit to potentially rushing a throw, or being lazy, not putting it to arms extension.

Lessons:
Drogue packing does matter.
Lazy/rushed/less than arm extension throws can cause a malfunctioned drogue.

I attached the only picture I could find of a drogue throw. Nice scenery, but not a very pretty drogue bridle.

Martin


"Just a quick note on PC (Drogue)/bridle entanglements from a BASE perspective. I'll use PC, though I know in this instance you are talking about a drogue.

In BASE, these are fatalities, so a lot of thought goes into preventing them. Three main causes:

First, folding the bridle on top of the PC rather than inside the mesh bottom causes your PC to have to pass through a wad of bridle as it opens. It may not be practical on a tandem drogue to Mushroom pack or pack the bridle inside the mesh, but we do that to prevent this very thing.

Second, flipping the PC. After you are packed, put your rig on and pitch your PC. Betcha a donut you flick your wrist, which flips the PC over backwards and causes the bridle to unfold in front of the PC. Again the PC must pass through the bridle. Reversing your grip and throwing your PC straight out may help prevent this.

Finally, lazy throws. Skydiviers get used to the wind taking their PC away from them. BASE jumpers are taught to pitch with authority. "Pitch like your life depends on it. It does." Is a common saying. I see many skydivers not throwing their PC to bridle stretch, or even worse, pulling it out and holding it for an instant before releasing it, which causes a greater risk of this malfunction.

I don't claim to be an expert, just sharing what I have learned in a similar sport that spends a heck of a lot more time worrying about PC packing and deployment than is generally necessary in skydiving. "
Experience is what you get when you thought you were going to get something else.

AC DZ

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I'd still like to know what caused it. This will probably never be solved though.

The other TI was watching when this drogue was packed.

I don't remember the s folds being too long but who knows...
DS #149
Yes I only have 3 jumps...it's the magic number dude.

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I've come to the conclusion/opinion that this mal is caused by a rushed, or otherwise fast deployment of the drogue into the burble. If the tandem pair is somewhat on their left side, you're putting the drogue out in the burble. I've decided to put the drogue out at arms extension, and let the bridle extend in the realative wind basically pulling the drogue out of my hand. My thinking is that the bridle is then fully extended, reducing or eliminating the chance of the drogue passing through a wad of bridle on it's way up.

After having this happen the second time, I had to get my head around it in order to be comfortable again. I need to always expect the best, and be prepared for the worst, as opposed to in the back of my mind expecting shit to not work.

Martin
Experience is what you get when you thought you were going to get something else.

AC DZ

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I've decided to put the drogue out at arms extension, and let the bridle extend in the realative wind basically pulling the drogue out of my hand. My thinking is that the bridle is then fully extended, reducing or eliminating the chance of the drogue passing through a wad of bridle on it's way up.



Not being a TI, perhaps I'm confused, but how is this plan different than your previous comment where you said it's not a good idea to briefly hold your PC out to the side before releasing?
Every fight is a food fight if you're a cannibal

Goodness is something to be chosen. When a man cannot choose, he ceases to be a man. - Anthony Burgess

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Not being a TI, perhaps I'm confused, but how is this plan different than your previous comment where you said it's not a good idea to briefly hold your PC out to the side before releasing?



I think that someone else said that.
Experience is what you get when you thought you were going to get something else.

AC DZ

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Quote



Not being a TI, perhaps I'm confused, but how is this plan different than your previous comment where you said it's not a good idea to briefly hold your PC out to the side before releasing?



I think that someone else said that.



Quote

I see many skydivers not throwing their PC to bridle stretch, or even worse, pulling it out and holding it for an instant before releasing it, which causes a greater risk of this malfunction.



This is the comment I was referring to.
Every fight is a food fight if you're a cannibal

Goodness is something to be chosen. When a man cannot choose, he ceases to be a man. - Anthony Burgess

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Quote

I see many skydivers not throwing their PC to bridle stretch, or even worse, pulling it out and holding it for an instant before releasing it, which causes a greater risk of this malfunction.



This is the comment I was referring to.



Ah, that was actually the comments of someone which came to me in a PM. I also spoke to the issue of posting PMs.

Martin
Experience is what you get when you thought you were going to get something else.

AC DZ

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"I've decided to put the drogue out at arms extension, and let the bridle extend in the realative wind basically pulling the drogue out of my hand."

.....................................................................

Yes,
I had a boss who used to do that. But it just created another problem. As the (delicate F-111) drogue rubbed up the (abrasive) Kevlar bridle, it burned dozens of holes.
His riggers were "fully-employed" patching drogues.

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"I've decided to put the drogue out at arms extension, and let the bridle extend in the realative wind basically pulling the drogue out of my hand."

.....................................................................

Yes,
I had a boss who used to do that. But it just created another problem. As the (delicate F-111) drogue rubbed up the (abrasive) Kevlar bridle, it burned dozens of holes.
His riggers were "fully-employed" patching drogues.



I had not thought of that, I'll keep an eye on my drogues. 2000 tandems, and I'm still always thinking, and changing what I do.
Experience is what you get when you thought you were going to get something else.

AC DZ

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I thought that I'd bring this one back to the top. Mike had his first drogue half hitch last weekend. He was running hand cam, so had the opportunity to review his drogue deployment. He was very stable belly to earth and put the drogue out into clean air. I think that it was just a bit rushed, and may not have been out to full arm extension.

A deliberate, full arm extension deployment should reduce or eliminate this problem. My opinion, if the drogue bridle has had time to fully extend, you won't be tossing into a tangle of bridle. Doesn't take a "hesitation" just get the thing out to full arm extension and be deliberate about it.

He had a clean main deployment, though it was fairly slow to extract the bag from the container.

Attached picts for your education and enjoyment.

Edit: I just noticed that this thread predates the Tandem specific thread. Maybe a Moderator will move the whole thing over to Tandem?

Martin
Experience is what you get when you thought you were going to get something else.

AC DZ

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Weak throw is an issue... As the BASE jumper, whose email you posted pointed out-anytime the bridle can get on the top skin of the Drogue/PC, bad stuff can happen.

Drogues are different than PC's, They are bigger, the Bridle they are attached to is wider and lastly; they are anchored by the drogue release system (to the tandem pair). At the end of the day both PC's and Drogues ARE smaller parachutes...

With that in mind-pretty much everyone who teaches packing to any audience at any level will teach VARIATIONS of 4 basic truths: 1) Lines in the center, fabric out. 2)Slider/Reefing system properly positioned. 3) line stows clean and organized to include locking stows. 4) container closed properly with bridle routed correctly.

Whether it is a PC or a drogue-it is a small canopy. If you put any part of the mesh or the bridle on the top skin-you are essentially packing the "lines" on the outside of the canopy. Furthermore, by rolling any part of the top skin around lines on the top skin you are begging for a line over, with no "lines" you get a "bridle over." Add a big burble, low air speed, weak toss, more fabric, longer "bridle" (applicable in BASE/Tandem AND most modern WS set ups), etc. and you have a potential for knots or more correctly-hitches. (Basically, the bridle is set up for failure by being packed in the wrong place and then exponentially worsened by other variables sending the apex of the drogue tumbling through a ball of crap. The amount of material, fact that there is an "anchor" (tandem pair) takes it the point of totally cinching off. (My guess is that improperly folded skydiving PC's don't routinely fail in this manner because they produce enough drag to clear the curved pin and usually only induce a "slow" opening)...

During my tandem course the course examiner talked at length about the importance of what I outlined above as a TI at the DZ had just had the "half hitched drogue, near terminal goat rope" happen to him. In his case he had a very capable camera man who captured the entire thing on his head. Best part of that video is the TI mouthing "are we good?"(because he knows they are accelerating and the video guy is head down) and the video guy shaking his head "NO!"...

My opinion is that if you keep the bridle inside the mesh AND set the drogue with certainty (EDIT TO ADD) AND set the drogue into the relative wind-you will not have issues. Another side of the argument is that putting the bridle in constant contact with the mesh can increase the wear on said mesh unnecessarily; reducing drogue/PC life span. (Actually had a huge argument with a packer about this). My view is that drogues/PC's are designed to be replaceable components, they have a service life. Why would we put ourselves at risk for an emergency by trying to add 50 jumps to a pilot chute or drogue?

Cheers,

-Harry
"Sometimes you eat the bar,
and well-sometimes the bar eats you..."

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When something is going wrong, the same way and more then once in a relative short amount of time, I tell my instructors that the problem is probably not the equipment (if well maintain) neither the passenger but the instructor new bad habit!
Usually only by listening to the instructor I end up to a pretty good idea where the problem is, but first I ask them to sit back and try to find what they are doing compare to what they learn in there course. If they can't find it then I give them my opinion and if there is a video we have a look at it. If the instructor is not sure what it can be an outside instructor can be a very good advise.

Richard DZO UPT TIE
When you think you're good...this is when you become dangerous.

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